Telephone system



Feb. 1,1927. 1,615,941

1 C. Bf. FOWLER TELEPHONE SYSTEM.

Filed Angl 12, 1925 Patented Feb. l, 1&2?.

Uhll'l STATES PATENT OFFIQE.

CLARENCE B. FOWLER, OF QUEENS, NEW YORK, ASSIG-NOR TO WESTERN ELECTRICCOMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Application led August 12, 1925.

This invention relates to telephone systems and particularly to systemsfor interconnecting rural or magneto lines with common battery lines.

An object of this invention is to provide improved rural subscribers ormagneto lines suitable for interconnection With common battery linesthrough cord circuits that are ordinarily used for interconnectingcommon battery lines only.

A feature of this invention resides in the provision of means forsupervising connections over magneto lines. Other features oit theinvention are the provision of means for intermittently displaying asignal at the central oitice terminal of a magneto line when asubscriber on said line is calling by actuating his generator; fordisplaying a steady signal after the subscriber on thisline has ceasedto operate his generator; for intermittently displaying the signal whenthe subscriber reoperates his generator either as a recall signal or adisconnect signal; and tor extinguishing thel signal when an operator atthe central oiiice makes connection with the subscribers line.

Other features not specifically mentionec will appear from the followingdescription, taken in conjunction with the accompanying drawings, inwhich Fig. 1 shows a complete circuit arrangement required for aconnection through a universal cord circuit betvreen a common batteryand a magneto line, the latter et which embodies the features of thisinvention, While Fig. 2 shows a modified "form of a. portion of themagneto line enibodying this invention.

Referring to Fig. 1, A represents a common battery subscribers station,B represents a rural subscribers station, Mreprescnts the magneto linecircuit arranged in accordance with this invention and associated withstation B, While C represents a universal cord circuit adapted iorintern connecting stations A and B. Considering the operation ozl thissystem on a conneet-ion from station B to station A, a call will beinitiated by the subscriber at sta tion B actuating ringing generator 10to produce an alternating current on the line. An alternating currentresponsive relay 11 will now become energized in an obvious circuitthrough the generator 10. The energi- Zation ci: relay '11 causes relay12 to operate in an obvious eircnit through the right hand Serial No.49,741.

armature and front contact of relay 11. The operation of relays 11 and12 causes the operation of relay 13 in a circuit from battery, left handWinding` of relay 13, armature and front Contact or' relay 12 to groundthrough the right hand armature and front contact of relay 11. Relays 12and 13 are new located up to the ground at the inner right hand armatureand 'front contact ot relay 13.

It should be noted that `with relays 11 and 13 operated, that is, duringthe period that the generator 10 is being operated, lamp 14 Will beintermittently lighted and extinguished. The original energizing circuitfor the lighting of lamp 14 may be traced from battery, lamp 14,resistance 16, outer right hand armature and front contact oit relay 13to ground. A short circuit for lamp 14 Will be alternately providedthrough the interrupter 15 as follows: battery, interrnpter 15, lefthand armature and front contact of relay 11, middle right hand arm-atureand Jfront contact of relay 13, resistance 17, resistance 16, outer lefthand armature and front contact of relay 13 to ground, th at is, lamp 14will therefore alternately be lighted or extinguished as long as thegenerator 10 is operated.

The operator at the central oflice wherein cord C is located, noting theintermittent -lashing of lamp 14 will interpret the signal as a callingvsignal from the subscriber at station B and answer it by inserting plug18 into jack 19. This connection of the plug and jack will close acircuit for relays 20 and 21 from battery, both windings of relay 21 inseries, sleeve terminals of the plug and jack, left hand armature andtrent contact of relay 13, middle Winding of relay 20 to ground. Relay21 will operate in this circuit Whereas relay 20 will not operate atthis time duc to the high resistance of the left hand Winding oit relay21.

The operator now actuates her listening key 29 to ascertain the numberWanted by the subscriber al: station B and .in so doing shunts theleftliand Winding of: relay 21 to battery associated with the lowerclosed contacts ot key 29, and relay 20 will therefore operate dueto thelowered resistance in the sleeve circuit. As relay 20 becomes ener gizedit provides a circuit from ground, inner right hand arniaturdrontcontact and iightband of relay 13, right hand armature and iront contactand right hand winding ot relay 2O to battery, and relay 13 being of thedifferential type will thereby release. The release of relay 13 opensthe circuit for relay 12 which will also release. The release of relay13 opens the circuits for lamp 11i through its outer and middle righthand armatures and front contacts so that the lamp 14 will now beextinguished. The releaseof yrelay 13 opens the circuit for relay at itslett hand arma-ture and front contact but closes the sleeve circuitinstead Athrough its inale-beforebreal contact through a resistance toground so that relay 21 will not release.

On the connection ot the plug 18 into `iack 19 relay 23 becomes`operated through a circuit from battery, lower right hand winding ofrepeating coil 2i, winding of relay 25, ring terminals ot the plug andjack, winding of relay 23, retardation coil 38, tip terminals ol" thejack and plug, upper right hand winding ot repeatingcoil 24 to ground.Relay 23 in energizing closes an. obvious circuit for relay 27 whichrelay in operating opens the full metallic circuit Vfor the line to thesubscriber at station B. rlhe opening oi this circuit is for the purposeof supplying a condenser circuit during conversation between theoperator and the subscribers sta tion B. As relay is included in thecircuit with relay 23, it operates immediately upon the insertion ofplug 18 into jack 19 and thereby prevents the operation of lamp 28 onthe operation of relay 21.

The operator now ascertains the number of the wanted subscriber andproceeds to extend the connection to the subscriber -at station Abyinserting plug 30 into jack 31. As is well known in the art, relay 32operates through the sleeve circuit closing a circuit for lamp 33 whichlights as a supervisory signal. The operator now operates her ringingkey 26 and applies ringing current from the source and ground 36 as iswell known in the art. This operation calls the wanted subscriber atstation A and when this subscriber answers the call, relay 34 operatesand extinguishes lamp 33. As is evident from examination of the drawingthe connection willv now be completed between the stations A and B andthe subscribers at these stations may `begin conversation.

In case the subscriber at station B desires to recall the operator during this connection or to itransmit a ring-otl signal that theconversation is concluded, he operates generator 10. Relay 11 will thenagain be operated causing the relays 12 and 13 to be operated and thelamp 14 alternately lighted and eX- tinguished as hereinbeitoredescribed. As the operator does not know whether thesub scriber atstation B is ringing oft1 or desires to recall her, she will now operateher listening key 29 and thereby connect her operators set to the line.The operation of hey 29 causes relay 2O to operate as hereinbeioreexplained and this relay will in turn cause relays 12 and 13 to releaseprovince, or

course, that the subscriber has ceased ringing. Relay 13 in releasingcauses the sleeve circuit to be transferred from the ground through thewinding of relay 2O to ground through a resistance at themake-beforebreal contacts, so that relay 29 will now be released ashei'einbei'ore de cribed. rl`he opei'ator will now ascertain whether thecalling subscriber has disconnected or whether he desires to ina-keanother call. lt the calling subscriber has disconnected, the operatorl- Considering now the extension oit a call in the opposite direction,that is, from the coininon battery station A. to magneto station lil,the opera-tor will insert answering plug 18 into jack 31 on thereception of the usual indication from the subscriber at station A iffthat the connection is desired. 0n the insertion of this plug, relay 21will be operated but lamp 23 will remain unoperated as relay 25 willoperate the moment the connection between the plug and ack is made. Thecntoll relay of the calling line operates in series with both windingsof relay 21 so that the line lainp is extinguished immediately andirrespective of whether the operator has operated her listening key 29.The operator now operates her listening key 29 and ascertaining -thenumber of the wanted subscriber then inserts the calling plug 30 intojack 19 ot the line ot' the subscriber atstation B. As plug 3() isinserted in jack 19 relays 3ft., v23, and 27 will be operated and theyoperation of relay 27 opens the metallic circuit to the subscribeidsstation and substitutes therefor a condenser circuit for talkingpurposes as hei'eiiiljietore described whi le the operation ot' relay 3%prevents the lighting of lamp 33 on the obvious operation or relay overthe sleeve circuit.

In order to call station l5 the operator non' actuates ringing key 2band. thereby causes the release olf relays 35'-, 23 and 2.7 so that themetallic circuit `from the key 2G to the sul'iscribers line is againcomplete. A circuit is thereupon closed as follows: from the source oitringing current 35, lower inner contactsvo'f ringing key 26, ringingterminals of the plug 3() and jack 18, ring conductor of line M throughthe lower armature and back contactof relay 27, the subscribers loop,tip conductor of line M through the lil@ l ltl upper armature and backcontact of relay I', tip terminals of the jack and plug, upper alternatecontacts of the ringing key 2G to i ground. As it is necessary that somemeans for closing the metallic circuit to the subscribers station beprovided for ringing purposes, relay 23 operates only on direct currentand therefore releases on the operation of key 26 and does not operateon the appli cation of ringing current to the line. lWhen the ringingkey is restored to normal, relays 23 and 27 will again operate whereupona metallic circuit Will be opened and the condenser circuit. as shown,substituted, over which the two interconnected subscribers may carry ona conversation. llVhen the subscribed station B answers this call bylifting his receiver otl' the hook, the operator will release her keysand conversation "l 1? between the two subscribers may take place.

(in the. restoration of the receiver hook by the subscriber B at the endof the conversation and on the usual ring-off signal, the operator Willtest th-e Wanted subscribers line as hereinbefore described and restorethe line to normal by removing plug 30 from jack 19 if the subscriber atstation B does not desire to secure another connection.

lVhen the common battery subscriber at station A replaces his receiver,relay 25 Will be tlE deenergizcd whereupon lamp 28 will become lightedin an obvious circuit to ground through the armature and front contactof relay 2l'. The operator Will now remove plug 18 from jack 81 andrelay 21 and lamp 28 will be restored to a normal condition.

lt Will be noted therefore that by the means outlined as above, thesubscribers equipped with different types of lines may easily andexpeditiously be associated with cach other and that in accordance withthis invention means for properly supervising such connections isprovided.

Referring now to liig. 2 of the drawings, it the leads a, Il), and c areconnected at the line X ot' Fig. 1 in place of the equipment shown belowthis line, a modified form of the invention may be provided.

ln this case, if, for example, a connection is desired from thesubscribers station B, relay 1l will become operated causing relay 12fto operate in an obvious circuit. The operation ol'V relay 12 closes anobvious circuit for lamp 114: from ground through the interruptor V15and the lamp 141-. `will there fore he alternately lighted andextinguished as this circuit is alternately completed or opened throughthe interruptor 15. The operation of relay 12 also closes the followingcircuit for relay l1: battery, armature and back Contact of relay 2G',Winding of relay 41, inner right hand armature and liront contact ofrelay 12 to ground. Relay Ll1 will close a locking circuit for itself toground, through its outer right hand armature and front contact. lt willtherefore be seen that as long as the generator 1() is operated lamp lewill be alternately operated and extinguished to indicate to theoperator at C that a connection is desired.

lf the subscriber at station B ceases ringing lamp 1li will be steadilylighted by the release of relays 11 and 12. This circuit for maintaininglamp 14e steadily lighted, may be traced as follows: battery, lamp l-l,left hand armature and back contact of relay 12', inner right handarmature and front contact of relay 4:1 to ground. W hen the operator atC answers this call, relay 20 Will be operated in the same manner asvwas relay 2O in Fig. 1. On the operation of relay 20 the circuit forrelay 41 Will he opened at the armature and back Contact of this relayand consetpiently lamp 14 Will beextinguished.

lf the subscriber at station B desires to recall the operator at` C orgive the usual ring-off signal he may operate his generatorI 1() ashereinbefore described causing the operation of relays 11 and 12 insucces-l sion. 0n the operation of relay 12 lamp 14 Will be alternatelylighted and extinguished by the interrupter 15 thereby calling` theattention of the operator to this connection. As relay 20 is nowoperated relay 40 will become operated over a cir- L cuit as follows:battery, armature and front contact of relay 20, winding of relay 40,outer right hand armature and front contact of relay 12 to ground. Relayl0 Will close a locking circuit for itself through its outer' right handarmature and front con,- tactto ground so that when the subscriber atstation B ceases ringing, the lamp 14 will be steadily lighted. Thiscircuit may be traced as follows: battery, lamp 141/, left hand armatureand back contact of relay 12', inner right hand armature and frontcontact of relay 4 0 to ground. lf this signal from the subscriber atstation A is a ring-ott signal, the operator at C simply removes plug 18from jack 19 thereby releasing relays 20 and 40 and extinguishing lamp14. lf another connection is desired by the subscriber at station B, theoperator at C removes plug 18 from jack 19 and either inserts theanswering plug 30 of the saine cord or the answering plug of any othercord circuit that she may find intuye convenient to employ forcoinliletii'ig this second connection. The insertion of this second pluginto jack 19 the second time' will cause it to function in the sainemani-ier as hereinbefore described.

What is claimed is:

1. ln a telephone system, a telephone line having a subscribers stationat one end thereof and central oliice switching equipment at the otherend thereof, a generator at the said station, a line lamp at the saidcentral oliice end of said line, and means lll) lllU

lilo

under control ot said generator for causcuit, a pair of condensersassociated with ing said line lamp to flash during the operation ot saidgenerator and to light steadily after the operation ot said generator.

2. In a telephone system, a telephone line having a subscriber"s stationat one end thereotl and central oliice switching equipment at the otherend thereof, a generator at the said station, a calling signal at thesaid central oliice end otsaid line, a cord circuit for connection withsaid line having means to control said signal, and means under controlot said generator for causing said signal to operate intermittentlyduring the operation ot said generator and to op eiate steadily afterthe operation o'f said generator, said means heilig eli'ective bothhetore and atter said cord circuit is connected to said line.

In a telephone system, a telephone line having a subscribe1"s station atone end thereof and central oiiice switching equip ment at the other endthereot', a generator at. the said station7 a calling signal at the saidcentral olhce end o't' said line, means under control of said generatorfor causing said signal to operate intermittently during the operationott said ge erator and to operate steadily after the operation ot saidgeneratonv a cord circuit tor connection with said line having means tocontrol said signal, means responsive to the connection of said cordcircuit to said line and under control oit said generator for causingsaid signal to operate intermittently during the operation oit saidgenerator and to operate steadily a'lter the operation of saidgenerator.

it. In a telephone system, a common battery subscribers station, amagneto suhscribers station, including a generator, an operator-sposition and a link circuit thereat` a line circuit tor extending saidmagnetic subscribers station to said operators position, a signa-lassociated with said line cirsaid line circuit, said link circuit beingadapted to interconnect said common hattery snhscriloers station andsaid line cirn cuit, means in said line circuit operated in response tothe actuation ot said generatorA tor causing said signal to operate in acharacteristic manner7 manually operable means in said link circuitameans responsive to the connection ot said link circuit and said linecircuit and to the operation of said manual means for restoring saidsignal and for including said pair ot condensers in said line circuit toform a talking path between said subscribers stations.

5. In a telephone system, a magneto subscribers station and a linecircuit therefor, a common battery subscriberis statiom a link circuitfor linterconnecting said stations, a signal in said line circnit anelectromagnetic means in said line circuit having a plurality otwindings7 an electromagnetic means lin said link circuit having aplurality of windings, a manually operable means in said linl; circuit,subscriber controlled means at said magneto station for causing theoperation of said signal in a characteristic manner, meansresponsive tothe connection of said link circuit and said line circuit forassociating one ot said windings ot said electromagnetic device in saidline circuit with all ot said .windings of the electromagnetic device insaid link circuit and means responsive to the actuation of said manuallyoperable means for causing the disassociation out one of the windings ofthe electromagnetic device in said link circuit from the electromagneticdevice in said line circuit whereby said signal is restored and saidelectromagnetic device in the line circuit caused to deenergize.

In witness whereof, I hereunto subscribe my name this i th day of AugustA. DL, 1925.

CLARENCE B. FOVLER.

